In London, President Obama and Prime Minister David Cameron praised the NATO mission in Libya, even as US legislators condemn Obama’s disregard of the War Powers Act.

British Prime Minister David Cameron, right, and US President Obama hold a joint press conference at Lancaster House in London on Wednesday, May 25. Obama and Cameron confronted complex security debates over Afghanistan, Libya, and economic growth.

WashingtonBoth President Obama and British Prime Minster David Cameron said in London Wednesday thatNATO’s military campaign in Libya is going “extremely well” – though apparently not well enough to meet its goals and end any time soon.Skip to next paragraphSpeaking after two days of showcasing the “essential” US-UK relationship, the two leaders said after a barbeque at 10 Downing Street that more “patience and persistence” will be required in the international coalition’s two-month-plus air campaign against Libyan leader Muammar Qaddafi.

The call for patience contrasted with early assumptions. When a US-led bombing campaign was launched against Colonel Qaddafi’s forces March 19, most believed that the Libyan regime’s remaining days were few. More than 60 days later, protests are mounting in Congress over Obama’s failure to secure congressional approval for the Libyan campaign as called for in the War Powers Act.

Both Mr. Obama and Mr. Cameron said that while the mission’s objective – as laid out in a MarchUnited Nations Security Council resolution – is to protect Libyan civilians and not explicitly “regime change,” they could not imagine how the mission could end without the departure of Qaddafi.

“Time is working against Qaddafi, and he must step down from power and leave Libya to the Libyan people,” Obama said. “It is impossible to imagine a future for Libya with Qaddafi still in power,” Cameron said for his part. “He must go.”

Despite the two leaders’ singular vision on Qaddafi, Cameron was unsuccessful in convincing Obama to commit more and different US resources to the NATO campaign. The British and the French are reportedly planning to add attack helicopters to the mission arsenal.

Obama said the US would continue to deploy resources that are unique to the US military, such as the Predator drones that are assisting NATO bombing raids. But he cautioned against buying into the idea that the US is holding back some magic bullet that could end the campaign quickly.

“I think there may be a false perception that there are a whole bunch of secret super-effective air assets in a warehouse somewhere that can just be pulled out and that would somehow immediately solve the situation in Libya,” he said. “That’s not the case.”

The president’s suggestion that the Libya campaign – and US participation in it – are likely to go on for a while may not be well received in Washington.

Republicans in both houses of Congress have introduced resolutions declaring the Obama administration in violation of the War Powers Act, 1973 legislation that calls on the president to seek congressional approval in the first 60 days of a military engagement. Obama finally did write a letter to congressional leaders last Friday, asking for congressional support for continued military engagement in Libya, but in the meantime US military participation continues in the absence of congressional approval.

Criticism of Obama’s use of force in Libya is not limited to the Republican side of Congress. Sen. Jim Webb (D) of Virginia said in an interview with Politico Wednesday that “Congress has basically been frozen out” of the US effort in Libya.

In Senate Armed Services Committee testimony Tuesday, Senator Webb said the Libya mission was launched despite the fact that “we were not under attack, we were not under a threat of an attack, we were not implementing a treaty, we were not rescuing American citizens, we were not responding directly to an incident.” Launching hostilities in this context “could set a very disturbing precedent for how decisions are made for the use of force,” he added.

In the Politico interview, Webb never mentioned the UN resolution authorizing international forces to protect Libyan civilians from Qaddafi’s threats, which is the justification both Obama and Cameron have consistently invoked and which they reiterated Wednesday in their London comments.

But Ivan Eland, a senior fellow at the Independent Institute in Washington, says Obama has gone farther than recent presidents in disregarding Congress’s constitutional role in war authorization – and he says it’s time for Congress to reassert itself.

“The framers of the Constitution thought that one of the biggest threats to citizens’ liberty was incurring the cost – in blood and treasure – of profligate wars, which were started by kings and leaders for their own aggrandizement,” Dr. Eland says. In light of that, “the founders put most of the constitutional war powers, including the power to declare war, in the people’s branch of government – the Congress – not the executive,” he adds.

He blames the onslaught of an “imperial presidency” since the Korean War for a usurpation of Congress’s war powers, and adds that Obama’s disregard of the War Powers Act is the latest in that process.

Eland says Congress should “reassert its constitutional power” and demand a withdrawal of US forces from the Libya mission – but chances of that happening any time soon look extremely remote.